A typical period lasts between 2 and 7 days. Most people experience bleeding for about 5 days, though anywhere in that range is normal. The full menstrual cycle, measured from the first day of one period to the first day of the next, runs 24 to 38 days.
What Counts as a Normal Period
International guidelines from FIGO (the global authority on obstetrics and gynecology) define a normal period as one lasting up to 8 days. Bleeding that consistently runs longer than 8 days is classified as prolonged menstruation. The heaviest flow usually happens in the first 2 to 3 days, then tapers off. Some people have a day or two of light spotting at the end, which still counts as part of the period.
Your cycle length matters too. A normal cycle falls between 24 and 38 days. Cycles shorter than 24 days are considered frequent, and those longer than 38 days are considered infrequent. For people between ages 26 and 41, cycles that vary by more than 7 days from month to month are classified as irregular. Younger adults (18 to 25) and those over 42 get a slightly wider margin of 9 days of variation before it’s considered irregular.
How Periods Change With Age
Periods don’t stay the same throughout your life. In the first year or two after menstruation begins, cycles are often longer and less predictable. It can take a few years for the hormonal signals that drive ovulation to settle into a rhythm, so teenagers frequently experience periods that vary in both length and heaviness.
At the other end, perimenopause brings similar unpredictability. As estrogen levels rise and fall more erratically, periods may get longer or shorter, heavier or lighter, and you may skip some entirely. If your cycle length shifts by 7 or more days consistently, that’s often a sign of early perimenopause. Going 60 or more days between periods suggests late perimenopause. This transition typically starts in the mid-40s but can begin earlier.
How Birth Control Affects Period Length
Hormonal birth control is one of the biggest factors that changes how long you bleed, and sometimes whether you bleed at all.
Standard combination pills are designed around a 4-week cycle: 3 weeks of active hormone pills followed by 1 week of inactive pills. Bleeding happens during that inactive week and is technically withdrawal bleeding rather than a true period. It’s usually lighter and shorter than a natural period. Extended-cycle pills stretch the active phase to 84 days (12 weeks), so you only bleed about once every 3 months during a 1-week break. Continuous-use pills eliminate the break entirely, meaning no scheduled bleeding for a year or longer.
Hormonal IUDs gradually reduce both the frequency and duration of periods. After one year with a higher-dose IUD, about 20% of users stop having periods altogether. By two years, that number climbs to 30 to 50%. The injectable contraceptive follows a similar pattern: after one year of use, 50 to 75% of users report no periods at all, and the likelihood increases the longer you use it.
Breakthrough bleeding, which is spotting or light bleeding between expected periods, is common in the first few months after starting any hormonal method. It usually settles down on its own.
Periods After Childbirth
There’s no fixed timeline for when periods return after having a baby. If you’re breastfeeding, your period may not come back for months, and in some cases over a year. The hormones involved in milk production suppress the signals that trigger ovulation. Once your periods do return, they’re often irregular at first, especially if you’re still nursing. As you reduce breastfeeding, cycles typically settle back into their pre-pregnancy pattern.
What Causes Periods to Last Too Long
Bleeding that consistently lasts more than 7 to 8 days has a range of possible causes. Hormone imbalances are the most common culprit. When the hormones controlling your cycle are out of sync, the uterine lining can build up unevenly and shed for longer than normal.
Structural issues in the uterus also play a role. Fibroids (noncancerous muscle growths) and polyps (small tissue growths on the uterine lining) can both cause heavier, longer bleeding. These are common, especially in people over 30, and are usually detected with ultrasound. In rare cases, prolonged bleeding can signal something more serious like a precancerous change, which is why persistent changes in your bleeding pattern are worth getting checked.
Signs Your Bleeding Isn’t Normal
Some changes in your period are harmless variations. Others point to something that needs attention. The CDC highlights several specific warning signs of abnormal bleeding: periods lasting longer than 7 days, soaking through a pad or tampon every hour or more on your heaviest days, passing blood clots larger than a grape, or bleeding so heavy it limits your ability to work, exercise, or go about your day. A history of being told you’re low in iron or being treated for anemia alongside heavy periods is another signal, since chronic blood loss is one of the most common causes of iron deficiency.
Heavy periods can also be a sign of an underlying bleeding disorder, particularly if you bruise easily, get frequent nosebleeds that last more than 10 minutes, or experience excessive bleeding after dental work or minor procedures. These patterns together suggest your blood may not be clotting as efficiently as it should.